The principal overall objective of this research project is to understand the developmental mechanisms which operate to assure orderly and functionally appropriate connections in the anuran visual system. Investigation of these mechanisms is largely predicated on the development of an electrophysiological recording technology which will allow the routine isolation of central nervous system neurons. Visually evoked activity in such neurons can then be used as an assay for the presence of afferent retinal synapses in animals subjected to a variety of experimental manipulations designed to reveal the operation of various developmental mechanisms. Of particular concern is clarification of the role of two specific mechanisms: the restriction of synaptic potency of individual retinal ganglion cells and the use of visual experience. BIBLIOGRAPHIC REFERENCES: Grobstein, P. and Chow, K.L. Receptive field organization in the mammalian visual cortex: the role of individual experience in development. In G. Gottlieb, ed., Neural and Behavioral Specificity. New York: Academic Press, 1976. Grobstein, P. and Comer, Christopher. Differences in Development of Adult Relative Eye Position in Xenopus and Rana. Neurosciences Abstracts 2:195, 1976.